A boy plays in a bucket while waiting for his mother to fetch water from a nearby hand pump to bathe him, Chennai, December 30, 2013.

Babu / Courtesy Reuters

The United Nations has always had lots of targets, goals, and declarations. You probably didn’t know, for example, that 2014 is the International Year of Family Farming and the International Year of Crystallography -- or that you are currently living through the Decade of Action for Road Safety. Such initiatives often reflect good intentions but rarely prove consequential. Between 1950 and 2000, at least 12 UN resolutions called for some form of universal education. In 1961, the so-called Addis Ababa Plan pledged that primary schooling in Africa would be “universal, compulsory and free” within two decades. Twenty years later, nearly half of all African children were still out of school. Countless other efforts promised equally lofty achievements, from gender equality to world peace, that never materialized.

But in 2000, something remarkable happened: the UN channeled its noblest aspirations into something more concrete. One hundred heads of state and 47 heads of government -- the largest meeting